Hatch seal

ABSTRACT

A hatch in road or rail tanker (2) includes a hatch cover (7) mounted in a flange (8) of a compartment manhole (9). In order to prevent leaks from the hatch cover (7), a band (13) is welded to the top of the tank (2) around compartment manhole (9). The band (13) includes an outwardly concave flange (14) providing a groove for receiving a hatch sealing device (15). The hatch sealing device (15) includes a generally cylindrical rubber cylinder having an open end and a closed end closed by a seal membrane, also of rubber. Around the inside of the rim forming open end there is provided an internally extending lip shaped to fit into concave flange (14). Around the outside of the cylinder is provided a split ring of metal, the ends of which are drawn together in order to radially compress the cylinder and thus seal it around the flange (14).

BACKGROUND OF THE INVENTION

This invention relates to sealing devices, and particularly to a devicefor sealing a hatch of the type provided in tankers, submarines, etc.

As is well known, such hatches are prone to leaking. For example, inroad and rail tankers, the or each hatch provided at the top of thetanker comprises a compartment hatch cover which fits over thecompartment manhole. The hatch cover is provided with a number offeatures including a pressure vacuum vent, a dip tube, and an inspectionhatch. Although it will be apparent that leaks could occur at each ofthe features in the hatch cover, as well as the edge of the hatch coveritself, when there is an accident such as the tanker rolling over, suchleaks even occur when the tanker is normally parked on an incline.

BRIEF SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a sealingdevice for a hatch which can be positioned around a leaking hatch toprevent, or at least reduce leakage.

Accordingly, the invention provides a sealing device for a hatch, thesealing device comprising a generally cylindrical member having an openend for fitting around the hatch, said member having its other endclosed in a fluid-tight manner, and means for maintaining thecylindrical member in radial compression against a flange providedaround the hatch to seal said cylindrical member to said flange.

The flange could be a flange on a wall supporting the hatch cover, orcould be a separate flange attached, for example by welding, around thehatch.

In a preferred embodiment, the means for maintaining the cylindricalmember in compression comprises a split band arranged around thecylindrical member and having means for pulling the two ends of thesplit band together so as to tighten the band around the cylindricalmember. Preferably, the means for pulling the two ends togethercomprises a tongue attached to one of the ends and a lever rotatablymounted to the other of the ends and biased against the tongue, whereby,when the lever is rotated, the tongue is biased thus moving the one ofthe ends towards the other of the ends.

Preferably, the tongue slides within a guide in the other of the endsand is provided with a flange, through which extends a longitudinalmember, biases against the flange and coupled to the lever at a pointadjacent the rotational axis of the lever. The longitudinal member ispreferably provided with means for adjusting the bias of the member.

In one embodiment, the open end of the member is provided with a liparound the rim thereof, the lip being adapted for fitting to a groove inthe flange around the hatch.

In another embodiment, the open end of the member can be fitted over aflange having a ridge therearound for compressing over the ridge.

According to a second aspect, the invention provides a substantiallycylindrical band for permanently attaching around a hatch in a surfaceof, for example, a road or rail tanker or a submarine, the cylindricalband having a flange to which the hatch sealing device as describedabove can be sealed.

The flange can be provided with a ridge or a groove to which the memberdescribed above can be sealed.

According to a third aspect, the invention provides a road or railtanker having one or more cylindrical bands of the type described abovepermanently attached thereto. The sealing device includes an annularspacing assembly, said annular spacing assembly having an internaldiameter sized to engage the outermost surface of the hatch and anexternal diameter sized to engage the innermost surface of the generallycylindrical member, wherein said assembly is compressible by the meansfor radially compressing the generally cylindrical member.

In a fourth aspect, the invention provides a flange comprising asubstantially annular member for fitting around a hatch in a surface of,for example, a road or rail tanker or a submarine, the annular memberhaving sealing means around the internal diameter thereof for sealing toan upstanding wall of the hatch and being compressible by a hatchsealing device as described above.

Preferably, the annular spacing member is formed in at least twosegments to facilitate fitting the annular member around the hatch.Preferably, sealing means are provided between the contact faces of thesegments, as well as around the internal diameter of the annular member.The annular member can be of metal, plastics or rubber material.

In a fifth aspect, the invention provides a hatch sealing apparatuscomprising a hatch sealing device as described above, in combinationwith the flange formed by the annular member as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of hatch sealing devices and apparatus according to theinvention will now be more fully described, by way of example, withreference to the drawings, of which:

FIG. 1 is a schematic view of the rear portion of a conventional roadtanker;

FIG. 2 is a schematic cross-sectional view of a hatch in the tanker ofFIG. 1 with a hatch sealing device according to one embodiment of theinvention in position;

FIG. 3 is a cross-sectional view of the hatch sealing device shown inFIG. 2;

FIG. 4 is a side view of the hatch sealing device shown in FIG. 3showing the compression means;

FIG. 5 is a partial end view of the hatch sealing device shown in FIG. 3with the compression means in position;

FIG. 6 is a schematic cross-sectional view similar to that of FIG. 2with a hatch sealing device according to a second embodiment of theinvention in position;

FIG. 7 is a plan view of a flange forming part of a third embodiment ofa hatch sealing device according to the invention;

FIG. 8 is a cross-sectional view of the flange of FIG. 7 along lineVIII--VIII;

FIG. 9 is a cross-sectional view through a part of the flange of FIG. 7looking from above; and

FIG. 10 is a schematic cross-sectional view similar to that of FIG. 2with a hatch sealing device according to a third embodiment of theinvention including the flange of FIGS. 7, 8 and 9 in position.

DETAILED DESCRIPTION OF THE DRAWINGS

Thus, as shown in FIG. 1, a conventional road tanker 1 including a tank2 mounted on a chassis 3 supported by wheels 4 is provided with aplurality of compartment hatches 5 along the top of the tank 2 toprovide access to the plurality of tank compartments 6 forming the tank2.

As shown in more detail in FIG. 2, the compartment hatch 5 includes ahatch cover 7 mounted in a flange 8 of a compartment manhole 9. Thehatch cover 7 is provided with a pressure vacuum vent 10, a dip tube 11and a loading/inspection hatch 12, which is hingedly mounted to thecover 7. As mentioned above, leakage of fluid from the tank 2 can occurat flange 8 if the cover 7 is not properly sealed thereto, from pressurevacuum vent 10 and dip tube 11, if they are not properly sealed and fromloading/inspection hatch 12 if it is not properly sealed to cover 7.Such leaks are especially likely in the event of an accident where thetanker is rolled over. However, it has been known for leaks to occureven when the tanker is upright but parked on an incline.

Thus, in one embodiment of the invention, a cylindrical band 13 iswelded to the top of the tank 2 around compartment manhole 9. The band13 includes an outwardly concave flange 14 providing a groove forreceiving a hatch seal 15.

As more clearly shown in FIG. 3, the hatch sealing device 15 comprises agenerally cylindrical member 16 formed of rubber. The member 16 has anopen end 17 and a closed end 18 closed by a seal membrane 19, also ofrubber. Around the inside of the rim forming open end 17 there isprovided an internally extending lip 20 shaped to fit into concaveflange 14 of band 13. On the outside of both open end 17 and closed end18, there are provided clip portions 21 and 22, respectively, betweenwhich is retained a split ring 23 of metal. The internal sides ofcylindrical member 16 and lip 20 are preferably fluted, as shown, inorder to reduce the amount of pressure required to radially compress thecylindrical member 16.

The compression is carried out by drawing together the two ends 24 and25 of split ring 23. As best shown in FIGS. 4 and 5, the ends 24 and 25of split ring 23 are drawn together by a lever and tongue arrangement. Atongue 26 is welded to end 25 of split ring 23 and slidably passesthrough a guide 27 in end 24 of split ring 23. The end of the tongue 26opposite to that welded to end 25 of split ring 23 is provided with atongue flange 28. A sealing plate 29 is welded to the inner side ofsplit ring 23 at its end 25 and extends below end 24 of split ring 23which slidably passes over sealing plate 29.

An elongate bar 30 passes through an aperture in tongue flange 28 and isprovided with a compression spring 31 coiled around the member 30between tongue flange 28 and an end stop 32 threaded on one end ofmember 30 so as to be able to adjust the bias of compression spring 31.The other end of elongate member 30 is pivotably coupled to a lever arm33 at pivot 34. The lever arm 33 is itself pivotally mounted at 35 tomount 36 attached to split ring 23. The pivots 34 and 35 are spaced fromeach other so that, when lever 33 is pivoted about pivot 35, elongatemember 30 is pulled against the bias of compression spring 31, whichbiases tongue flange 28 such that ends 24 and 25 of split ring 23 arepulled together. This compresses, and maintains in compression, thecylindrical member 16 so as to tighten lip 20 within concave flange 14,and thus seal the cylindrical member 16 around the hatch.

Turning now to FIG. 6, there is shown a second embodiment, similar tothe first embodiment, in which all identical elements have the samereference numerals. As can be seen, in this embodiment, the lip 20around the open end of the member 16 is not present. In this embodimentit is not required since the band 13 is taller than that of the firstembodiment, and is provided with a convex flange 37 forming a ridge atan upper portion thereof. The hatch seal 15 is thus positioned over theflange 37 and compressed over the flange 37 to seal around it.

In an alternative to this embodiment, the hatch seal 15 could becompressed directly onto the flange 8 of manhole compartment 9 if theleakage occurs from the top of the hatch cover rather than from thelower portions of manhole compartment 9.

Shown in FIG. 10 is a still further embodiment of the invention, againwith the same elements having the same reference numerals as in theearlier embodiments. In this embodiment the member 16 again does nothave the lip 20 around its open end, and the hatch seal is generallyidentical to the hatch seal of the second embodiment. However, in thisembodiment, the band 13 is not present. Instead, there is provided aannular spacing assembly 38 formed of three segmented annular spacingmembers 39 and having a sealing element 40 extending around the innerside thereof. The annular spacing assembly 38 is more clearly shown inFIGS. 7, 8 and 9. The annular members 39 can be made of any suitablematerial, such as metal, plastics or rubber material and has a groove 41around the inner side thereof into which the sealing element 40 isfitted. Of course, if the annular member is itself made of a materialwhich will provide adequate sealing, a separate sealing element wouldnot be required. As shown in FIG. 9, which is a part cross-sectionalview looking from above the view of FIG. 7, the three segments formingthe annular member 39 are joined together at their contact faces bymeans of a tongue 42 and recess 43 arrangement. The sealing element 40is arranged to seal the contact faces when they are connected.

To use the hatch seal, the annular member 39 is disconnected into itsthree members 39 and positioned around the outside of the wall ofmanhole compartment 9 and then connected together such that the sealingelement 40 is positioned between the contact faces of the annular member39 and around the inner side thereof adjacent the wall of manholecompartment 9. The hatch seal 15 is then positioned over the spacingassembly 38 formed by the three annular spacing members 39 and thesealing element 40 and radially compressed in the manner describedabove. Radial compression causes the members 39 of the assembly 38 to betightly connected with the sealing element 40 sealing the contact facesand forming a tight seal between the inner side of the assembly 38 andthe wall of the manhole compartment 9.

It will be appreciated, that although only particular embodiments of thehatch seal and the way of compressing the cylindrical member have beendescribed, various modifications and improvements can be made withoutdeparting from the scope of the present invention.

For example, it will be appreciated that if the ring 13 is used, itshould be made of a material compatible with that of the tank to whichit is attached, for example by welding.

The split ring 23 should be made of material resistant to the fluid inthe tank, for example of stainless steel.

Furthermore, the cylindrical member, and the annular member forming theflange, if used, can be formed of any material which is substantiallyimpervious and/or resistant to fluid within the tank.

I claim:
 1. A combination of a sealing device and hatch comprising thehatch having a base and neck extending upwardly from said base forming apassage way closed by a cover; a flange spaced radially from the neckand extending upwardly from the base; the sealing device having agenerally cylindrical member with an open end fitting around the flange,said cylindrical member having its other end closed in a fluid tightmanner; and means for radially compressing the cylindrical member andmaintaining the cylindrical member in radial compression against theflange to seal said cylindrical member to the flange.
 2. The combinationaccording to claim 1 wherein said means for radially compressing thecylindrical member and maintaining the cylindrical member in compressioncomprises a split band arranged around the cylindrical member and havingmeans for pulling the two ends of the split band together so as totighten the split band around the cylindrical member.
 3. The combinationaccording to claim 2 wherein said means for pulling the two endstogether comprises a tongue attached to one of the ends and a leverrotatably mounted to the other of the ends and biased against thetongue, whereby, when the lever is rotated, the tongue is biased thusmoving the one of the ends towards the other of the ends.
 4. Thecombination according to claim 3 wherein said tongue slides within aguide in the other of the ends and is provided with a tongue flange,through which extends a longitudinal member biased against the flangeand coupled to the lever at a point adjacent the rotational axis of thelever.
 5. The combination according to claim 4 wherein said longitudinalmember is provided with means for adjusting the bias of the member. 6.The combination according to claim 2 wherein said split band is steel.7. The combination according to claim 1 wherein said cylindrical memberis formed of material which is substantially impervious and/or resistantto fluid within the hatch.
 8. The combination according to claim 1wherein the open end of the member is provided with a lip around the rimthereof, the lip being sized to engage a groove in the flangesurrounding the hatch.
 9. The combination according to claim 1 includingan annular spacing assembly, said annular spacing assembly having aninternal diameter sized to engage the outermost surface of the hatch andan external diameter sized to engage the innermost surface of thegenerally cylindrical member, wherein said assembly is compressible bythe means for radially compressing the generally cylindrical member. 10.The combination as claimed in claim 9 wherein said annular spacingassembly is comprised of at least two segments, said segments beinglockable to each other by complementary engaging formations.
 11. Thecombination as claimed in claim 10 wherein said complementary engagingformations are tongue and groove formations provided in adjacentsegments.
 12. The combination as claimed in claim 9 wherein said annularspacing assembly includes an inwardly facing annular sealing element.